Stair climbing exercisers are generally known in the art and may be categorized as either real climbing or simulated climbing exercisers. Real climbing exercisers are characterized by motor driven, escalator-type revolving staircases. Revolving staircases, however, are generally expensive, occupy a great deal of floor space and require a high degree of operator coordination. Accordingly, simulated climbing exercisers have been developed to overcome these drawbacks. Simulated climbers generally comprise a left and right pedals or steps and may be further categorized as having independent or dependent stepping action, both of which have inherent advantages and disadvantages depending on the needs of the individual user.
Dependent stepping action is characterized by the dependency of motion between the left and right steps. In particular, the left step moves up as the right step reciprocally moves down and vice versa. The reciprocal downward force imparted by the operator's stepping action results in an opposite upward force on the upward moving step. The advantage of this action is that no operator coordination is required. The action provides the operator with sensory feedback as to when he should lift each foot. Thus, the occasional, or possibly handicapped, exerciser is provided a safe simulated stair climbing exercise. The disadvantage of this action is that only a contrived step action is achieved resulting in fewer calories burned.
In contrast, independent stepping action is characterized by the independence of motion between the left and right steps. In particular, the movement of the left step has no effect on the right step and vice versa. Typically, each left and right step is equipped with a return spring. The return spring has sufficient force to return each step to a stepping position after the downward force is removed and the operator has lifted his foot in anticipation of the next step. The advantage of this action is that a different workout is achieved since the operator must lift his own foot with each step and may exercise each leg at a different level of effort. The disadvantage is that a greater level of coordination and/or strength is required to use such an exerciser. No upward force aids the lifting foot with each step or even provides sensory feedback as to when the operator should lift each foot.